# Copyright 2019 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Classes and functions implementing to Model SavedModel serialization."""

from keras.saving import saving_utils
from keras.saving.saved_model import constants
from keras.saving.saved_model import layer_serialization
from keras.saving.saved_model import save_impl


class ModelSavedModelSaver(layer_serialization.LayerSavedModelSaver):
    """Model SavedModel serialization."""

    @property
    def object_identifier(self):
        return constants.MODEL_IDENTIFIER

    def _python_properties_internal(self):
        metadata = super()._python_properties_internal()
        # Network stateful property is dependent on the child layers.
        metadata.pop("stateful")
        metadata["is_graph_network"] = self.obj._is_graph_network
        spec = self.obj.save_spec(dynamic_batch=False)
        metadata["full_save_spec"] = spec
        # save_spec is saved for forward compatibility on older TF versions.
        metadata["save_spec"] = None if spec is None else spec[0][0]

        metadata.update(
            saving_utils.model_metadata(
                self.obj, include_optimizer=True, require_config=False
            )
        )
        return metadata

    def _get_serialized_attributes_internal(self, serialization_cache):
        default_signature = None

        # Create a default signature function if this is the only object in the
        # cache (i.e. this is the root level object).
        if len(serialization_cache[constants.KERAS_CACHE_KEY]) == 1:
            default_signature = save_impl.default_save_signature(self.obj)

        # Other than the default signature function, all other attributes match
        # with the ones serialized by Layer.
        objects, functions = super()._get_serialized_attributes_internal(
            serialization_cache
        )
        functions["_default_save_signature"] = default_signature
        return objects, functions


class SequentialSavedModelSaver(ModelSavedModelSaver):
    @property
    def object_identifier(self):
        return constants.SEQUENTIAL_IDENTIFIER
